Hitachi GH 300 - Manual (Page 8)

Troubleshooting
8 311797F
Troubleshooting
PROBLEM CAUSE SOLUTION
Gas engine pulls hard (won't start) Hydraulic pressure is too high Turn hydraulic pressure knob counter clock-
wise to lowest setting.
Gas engine does not start Switch OFF, low oil, no gasoline Consult engine manual, supplied.
Gas engine doesn't work properly Faulty engine Consult engine manual, supplied.
Elevation Refer to Engine Repair Kit.
4.0 hp - 288678 / 5.5 hp - 248943 /
6/5 hp - 248944 / 9.0 hp - 248945
Gas engine operates, but displacement
pump doesn't operate Hydraulic pump valve is OFF Set hydraulic pump valve ON.
Pressure setting too low Increase pressure.
Displacement pump outlet filter (if used)
is dirty or clogged Clean the filter.
Tip or tip filter (if used) is clogged Remove tip and/or filter and clean.
Hydraulic fluid too low Shut off sprayer. Add fluid*.
Belt worn or broken or off Replace, page 12.
Hydraulic pump worn or damaged Bring sprayer to Graco distributor for repair.
Dried paint seized paint pump rod Service pump. See manual 311845.
Hydraulic motor not shifting Set pump valve OFF. Turn pressure down.
Turn engine OFF. Pry rod up or down until
hydraulic motor shifts .
Displacement pump operates, but output
is low on upstroke Piston ball check not seating properly Service piston ball check. See manual
311845.
Piston packings worn or damaged Replace packings. See manual 311845.
Displacement pump operates but output
is low on downstroke and/or on both
strokes Piston packings worn or damaged Tighten packing nut or replace packings.
See manual 311845.
Intake valve ball check not seating
properly Service intake valve ball check. See man-
ual 311845.
Suction tube air leak
Paint leaks and runs over side of wetcup Loosen wet-cup Tighten wet-cup enough to stop leakage.
Throat packings worn or damaged Replace packings. See manual 311845.
Excessive leakage around hydraulic
motor piston rod wiper Piston rod seal worn or damaged Replace these parts.
Fluid delivery is low Pressure setting too low Increase pressure.
Displacement pump outlet filter (if used)
is dirty or clogged Clean filter.
Intake line to pump inlet is not tight Tighten.
Hydraulic motor is worn or damaged Bring sprayer to Graco distributor for repair.
Large pressure drop in fluid hose Use larger diameter or shorter hose.
The sprayer overheats Paint buildup on hydraulic components Clean.
Spitting from gun Air in fluid pump or hose Check for loose connections on siphon
assembly, tighten, then reprime pump.
Loose intake suction Tighten.
Fluid supply is low or empty Refill supply container.
Excessive hydraulic pump noise Low hydraulic fluid level Turn sprayer OFF. Add fluid*.
Electric motor does not operate Power switch is not ON Turn power switch to ON.
Tripped circuit breaker Check circuit breaker at power source.
Reset motor switch.
*Check hydraulic fluid level often. Do not allow it to become too low. Use only Graco approved hydraulic fluid.